here is how criticals work in minecraft
Critical hits
A critical hit performed on a sheared sheep.
'Critical hits' are attacks that deal extra damage compared to regular attacks. Critical melee strikes, regardless of the weapon used, cause small star particles to fly out of the target who was critically hit. "Critical arrows", which occur when the bow is fired fully charged, leave a trail of the same small star particles as they fly through the air. Critical hits affect all damageable entities including players, mobs, paintings, boats and minecarts.
In melee, a critical hit occurs when a player attacks a mob while falling, not while jumping up. The attack deals a random amount of additional damage, up to 50% more (rounded down) plus one heart. This can be done by jumping. It can also be combined with sprinting to knock back the mob, although there is no extra knockback for a critical hit. The maximum damage from a critical hit depends on both the weapon/tool and its material (fists and arrows have no material):
Wood Gold Stone Iron Diamond
Sword 11 (Heart.svgHeart.svgHeart.svgHeart.svgHeart.svgHalf Heart.svg) 13 (Heart.svgHeart.svgHeart.svgHeart.svgHeart.svgHeart.svgHalf Heart.svg) 15 (Heart.svgHeart.svgHeart.svgHeart.svgHeart.svgHeart.svgHeart.svgHalf Heart.svg) 17 (Heart.svg ? 8.5)
Axe 8 (Heart.svgHeart.svgHeart.svgHeart.svg) 9 (Heart.svgHeart.svgHeart.svgHeart.svgHalf Heart.svg) 11 (Heart.svgHeart.svgHeart.svgHeart.svgHeart.svgHalf Heart.svg) 12 (Heart.svgHeart.svgHeart.svgHeart.svgHeart.svgHeart.svg)
Pickaxe 6 (Heart.svgHeart.svgHeart.svg) 8 (Heart.svgHeart.svgHeart.svgHeart.svg) 9 (Heart.svgHeart.svgHeart.svgHeart.svgHalf Heart.svg) 11 (Heart.svgHeart.svgHeart.svgHeart.svgHeart.svgHalf Heart.svg)
Shovel 5 (Heart.svgHeart.svgHalf Heart.svg) 6 (Heart.svgHeart.svgHeart.svg) 8 (Heart.svgHeart.svgHeart.svgHeart.svg) 9 (Heart.svgHeart.svgHeart.svgHeart.svgHalf Heart.svg)
Fist 2 (Heart.svg)
Arrow shot 10 (Heart.svgHeart.svgHeart.svgHeart.svgHeart.svg)